Ratchet-brake mechanism



Apr. 24, 1923. 1,452,784

R. H. BLACKALL RATCHET BRAKE MECHANISM Filed May 5, 1922 2 Sheets-Sheet l 5in/avuto@ Apr. 24, 1923.

' 1,452,784 R. H. BLACKALL RATCHET BRAKE MECHANISM Filed May 5, 1922 2 sheetsheet 2 y Patented pr. 24, 1923.

p Laage ROBERT HVBLACKALL, OF PITTSBURGH,

kPENrisvtvanre,` .assrenon To RATCHET BRAKE COMPANY, A CORPORATION OF NEW YORK.

RATGHET-BRAKE MECHANISM.

Application led May 5,

To allan/0m t may concern g Be it known that I, ROBERT H. BLACKALL, a citizen of the United States, residing` at Pittsburgh, in the county of Allegheny, State of Pennsylvania,`have invented certain new and useful Improvements in RatchetBrake Mechanisms yand I do hereby4 suitable clutch mechanism, converted into ay brake-applying movement of the brakestaff. In devices of this character, gravity, or some form of 'releasing mechanism for the brakes, as for instancesprings, is relied upon to rotate the brake-stad in the reverse direction, the said mechanism acting upon the chain to unwind the same. In practice, however, it lrequentlyhappens that the cha-in does not unwind freelyk and the device will stick and fail to release properly, because the turnsot they-chain yon the'staii become wedged or entangled one in another, become jammed against the brake-.statt support or other parts of the car, orv the staff binds in the end sill. In such case, the brake shoes will remain in contactwith the wheels leaving the brakes set or dragging. Because of this it is desirable vto provide means permitting the staff to be positively turned in I the reverse direction. In the usual construction, a spring;l supported capv is provided, which may be depressed manually, to connect'the brake-staff and. lever, so that by means of the lever, the staff may be rotated in the reverse direction. Tovoperate the cap, it is necessary that the operator hold the cap 4depressed during the reverse rotation of the brake-statt. In the present invention I provide means whereby the staff may be. clutched or coupled to the lever to be rotated Jforwardly tov set vthe brakes, or rearwardly to positively release the bra-kes, by moving said lever longitudinally ot the staff, the lever being moved in one direcan improvement inv 1922. serial No. 558,606.

tion to couple it to the staff to set the brakes, and in the opposite direction to coupleit to the statt to release the brakes.

In the drawings- 1 l V,Figure is a side view of the mechanism in position to operate the brakes, and with' the parts in one position, f

Figure 2 is a similar view with the parts in another position,

Figure 3 is a top plan view, v

Figure el is a section on the line le-4 of Figure 3, l

Figure 5 is a 'front view with the parts in release or neutral position,

Figure 6 is a similar view with the parts. in brake releasing position,

Figures 7 and 8 are sections onthe lines 7 7 and 8-8 respectively, ot Figure 4.1

In the present embodimentofthe invention, the brake-statt lis provided near its top, with a rred clutch section 2, secured thereto by means of a'pin 3, extending diametrical to the statt, and engaging the section. The iiXed clutch has teeth l on its upper tace, as shown, which: are adapted to cooperate with similar teeth 5' on a movable section G, which is connected to the operating` lever-)7 for the brake, in a manner to be presently described. The

movable clutch section 6 is in the form of housing, mounted to 'move vertically on Vthe stall', and the lever 7 is pivoted thereto by means oit a pin f8, in such manner that the lever may swing radially to the'staft', or into substantial parallelism therewith.

A cap 9 is secured to the top of the staff, above the housing 6, by means of a crosspin 10, and the lower edge of this cap carries a series ot clutch teeth 1l,`which :tace in the opposite directionv to ther teeth 4 of the fixed clutch section 2. The movablev clutch section or housing 6, carries a'second set of clutch teeth 12, whichare designed to cooperate with the teeth 11, and the teeth l2 face in the opposite direction to the teeth. Aebracket` 18 supports andI journals the etait, below the fixed clutch 'section 2, and this bracket carries oppositely arranged double cams, each consisting of portions 14 and l5. Each of the said p ortions is in the form of an incline, havingy at its upper edge a stop 16 and 17, respectively. The housing 6 carries a pair of oppositely arranged cams 18, each of which has a surface inclined in the opposite direction to the cam portions 14 and 15, and designed to cooperate therewith. A stop 19 is provided at the lower endioif each cam 18, and each cam is recessed, as indicated at 20, adjacent to the stop, the recess being` designed to receive the stop 16. When it lis desired to hold the movable clutch seci n Figure now disengaged, and the movable section tion in released position, that is out ot en gagement with the fixed section 2, the lever is moved tocause the cam surfaces 18 yto ride upon the cam surfaces 1i until the recesses 20 engage the stops 16 as shown in The clutch teeth L1- and 5 are of the yclutch is in` neutral position. The

` f lever cannot move further in. this direction,

the stops 16 and 17 locking the cam 18 between them, to preventoverthrow of the lever, such as might move the cams 18 beyond the cams lil- 15. vWhen it is desired to move the movable section into engagement with the fixed section or cap 9, the

- housing 6 is lifted bodily by hand to en- `Qjage the teeth 12 with the teeth 11.

In operation, when it is desired to set the brake, the brakeman swings the lever 7 outwardly, and oscillates the same. As the lever moves forwardly, the brake-stan is carried therewith, and as the lever moves .i for the brakes.

rearwardly the teeth 5 slip idly over the teeth 4i. A continuation of the oscillating movement willevent-ually tighten the brakes. When it is desired to release the brake, the staff is'moved by means of the lever toward brake tightening` position, untilfthe foot or holding pawlforthe stati', not shown, but which is usually arranged on the platform,

,may be released. After loosening-the foot pawl, the lever is released.v The rotation of the brake-staff from any cause, it be backed-oli7 by lifting the housing bodily,

` until the teeth 12 thereof engage the teeth 11 of the cap. Then so engaged and held,

, the brake-staff may be rotated rearwardly,

` 4and it necessary tok rotate it more than a convenient throw of the lever 7, the lever may be swung about the staii' forwardly to engage the clutch or cap 9 at another point. ItA will be understood that the bracket 13 is secured to a fixed supporhas for instance a car body or framing, and the said bracket provides a journal for the sta.

I claim:

1. In a mechanism of the class described, the combination with the brake-staff and the operating lever, of oppositely arranged ratchet-toothed clutch sections lixed to the stati' and spaced apart from each other, a movable section between said' fixed sections having a set of ratchet teeth on each end and mounted to move to cooperate with the sections in alternation, thereby to move the staff in either direction, and means for oscillating the movable section.

2. In mechanism of the class described, tbe combination with a brake-staff and the operating` leven, of oppositely arranged fixed clutch sections on the staff spaced apart from each other, a section movable on the staff between the Xed sections to cooperate with either thereby to move the stai in either direction, a lever for oscillating the movable section, and means controlled by the swinging of the lever rearwardly beyond a selected point for moving the movable section into inoperative position and for holding it in such position.

3. In mechanism of the class described, the combination with the brake-staff and the operating lever, of upper and lower fixed clutch sections spaced apart from each other, a movable section between the fixed sections, and mounted to move to cooperate with the sections in alternation, thereby to move the staff in either direction, an operating lever hinged to the movable section to swing radially tothe staff or into substantial` parallelism therewith, and means controlled by rearward swinging of the lever beyond a selected point 'for moving the movable section out of engagement with the lower ixed section into vinoperative position and for holding itin such position.

4:. In mechanism of the class described, the combination with the' brake-stai?, of upper and lower clutch sections secured on the staff in spaced relation one above the other, a movable section between said fixed sections and common to both, said fixed sections being oppositely arranged, and a lever pivoted to the movable section for operating the same, a fixed bracket in which the stati is journaled, said bracket and the movable section having` cooperating means for lifting the movable section out of engagement with the lowerinost ixed section, and controlled by the rearward swinging oi' the lever.

In testimony whereof I aiiix my signae ture,

ROBERT II. BLACKALL. 

